GPS Toolkit (GPSTk) 1.0 Released

rmach writes "Based on many years of work performed at ARL:UT, we have release GPSTk under the GNU LGPL. GPSTk is a cross platform library and set of applications that provides both fundamental and advanced GPS processing algorithms to the GPS and open source community. A wide array of functions are provided by the GPSTk library, including: RINEX I/O, ephemeris calculation, P-code generation, atmospheric refraction models, and positioning algorithms. GPSTk applications provided more concrete benefits to the user, including: cycle slip detection and removal, calculation of the Total Electron Content (TEC) of the ionosphere, position residual computation, and RINEX file manipulation. The library is about 41,000 SLOC with a COCOMO estimated cost to develop of about $1.3 million. You can also read more about it in the current issue (September '04) of Linux Journal."

Re:Not sure how this is useful...

[afidel]

No, it means you can do precise calculations with cheap equipment. Most of these functions cost thousand of dollars if done in hardware.

Track editing?

[Hanna's Goblin Toys]

When I bought my Garmin Etrex, I wanted to use it to store mountain bike rides and overlay them with maps. Easy, right? Bah! I spent two weeks trying to find a way to do this on my Linux box before giving up. I ended up paying out of my rear end to buy expensive Garmin maps and closed source software. Even then, I couldn't mix and match tracks, let alone cut and paste sections of them together to make trail maps.

The other featuer I've always wanted is to do profile slices of my rides to see climbing and descending rates, especially during races.

All in all this toolkit sounds hugely promising, as the last time I looked at SF.net/Freshmeat the capabilities were nearly nil. All I want is a simple import module, track overlay over free downloadable maps, and a track editor...

I'm going to be spending the evening trying to get this stuff working, hopefully it will provide a replacement to my current Garmin/Microsoft solution!

Re:Track editing?

[HighBit]

I actually have a HOWTO [lost-habit.com] on this...

I also have an (alpha-quality) script that actually automates making maps from gps data (using kismet)... maybe someday I'll get off my ass and finish it..

Re:Not sure how this is useful...

[afidel]

So, yes then...

Uh, No.

More precise != faster in fact precise generally == slower. You have to take more measurements to get the data needed for input into the more precise modeling algorithms, but it allows you to calculate location VERY precisely (down to mm if you can get measurements over a day or two).

Re:This is just a bunch of

[SsShane]

GIS (and GPS which go hand in hand) is a fast growing branch of IT. I worked network admin stuff and hated it, and then fell into a GIS position because the guy was leaving and I took to it easy because of my experience making Doom, Quake and UT maps (I am not joking). The computer science background helped of course. I love it so much, that I download MOLA data from the Mars Global Surveyor and make hight maps that depict what-if oceans (that one taxed my computer good), calculate the volume of Mons Olympus' caldera, and other useless stuff. GIS is a geek paradise.

Great! But....

[dannyelfman]

What hardware can I use this with?

Wasn't the Precision code classified?

[kamelkev]

In the GPS system, there are three kinds of codes: C/A code, P-code and Y-code.

Now last I checked the Precision (P) code was considered classified. Details about how this code was generated and how to decrypt it were considered military secrets.

I don't believe the P-code has anything to do with selective availability either, I think that the P-code is used for the militaries PPS, which is "precise positioning system".

Anyway, so how is that included in this suite? and further, what purpose does it serve to even have access to the p-code, as standard gps gear isn't even supposed to work with it?

You know the reason...

[hot_Karls_bad_cavern]

...look at the posting editor. i've said it before and i'll say it again, Michael is out of touch and generally posts pretentious articles. i'm thinking it's some sort of complex or something. Everything he posts is some YRO, obscure, anti-establishment laden attempt to boost his ego...or something. This is not a troll, it is an observation, but will most likely be modded a troll due to the dissenting nature.

Anyway, don't be shocked by his misguided ego - it's old and getting more so. Hell, his little "gnutella-still-free-for-all dept" on the Real story is evidence of his nature and was pointed out in this [slashdot.org] post. Michael is a liability and tired.

What this is

[thule]

Please correct me if I'm wrong, but this software is very important. This is the software that normally runs inside the GPS, not for drawing maps, but interpreting the GPS radio signals and calculating the lat/long numbers. Why would this be useful? Well, say, you take a project like GnuRadio and make your own GPS receiver. GnuRadio can demodulate the signals and convert it to data. This software would allow you to take the data you receive with GnuRadio and do something with it.

It seems to me that this is first time that code like this has ever been published under an open license.

Re:um, no.

[thule]

Really? What about these projects then:

GPS and GnuRadio [comsec.com]

and

OpenSourceGPS [earthlink.net]

The latter claims:

"The receiver requires at a minimum a 100 MHz 486 IBM PC with 640k RAM."

So it seems to be possible. Someone posted the GPSTk link to the GnuRadio mailing list with the hope of eventually getting GnuRadio the ability to do advanced processing of GPS signals.

I'm not a GPS expert... am I missing something here?

Dude, where's my phone?

[Doc Ruby]

What about the DGPS (Differential GPS) in our mobile phones that provide E911 (Enhanced 911) emergency phone service? IBM has mentioned an "Engine 18" that lets these superlight GPS receivers send their raw received data to a server for location processing. My Treo 600, with PalmOS5, is really spiffy. Is GPS another demand generator for smartphone Linux?

Re:LGPL!

[rmach]

Sorry, I just misread your post. Well I checked but the definition didn't quite fit ;-):

moron: An inferior olive size having a woody pulp and a large clingstone pit, growing in the mountainous and high-valley districts around the city of Moron, in Spain.

Re:Huh?

[GPSguy]

What you get from YOUR GPS is an autonomous position estimate.

What I get from my array of GPS receivers is a set of observables, including the pseudorange from the code phase measurements, and carrier phase information. When I get done processing, I have a set of baselines, a set of potential delays in the troposphere and ionosphere, doppler shifts for the satellites in view, timing deltas, and information on signal multipath propagation.

When I report something out, I can give horizontal positions with respect to a known coordinate system to about 1 cm (2sigma RMS) and vertical estimates (referenced to the WGS84 ellipsoid) on the order of 2 cm (2sigma RMS). Given a good gravity model, I can estimate geoid height differences to about 3 cm.

Given code phase observables from a satellite-borne receiver, I can make reasonable estimates of the satellite's ephemerides and state vector, provided 3 sets with a temporal spread of about 20 minutes. Given code and carrier data I can derive the state vector in less time and with better accuracy.

I can estimate the amount of precipitable water in a vertical column of atmosphere above a GPS receiver site.

I can make estimates of the ionosphere's total electron count.

There's more.

For the record, I've been doing all of the above, for several years.